PHP GD library issue

Hello, i get this error?

[warn] [client xx.xx.xx.xx] mod_fcgid: stderr: PHP Fatal error: Call to undefined function imagecreatefrompng() in /home/DEMO/public_html/engine/modules/antibot.php on line 119, referer:

This is the problem i see in my site… when try to change my AVATAR it return empty page, also captcha not showing. When i install virtualmin on CENTOS longtime ago this never happen but now i change to Debian and i got this problem.

i saw some answers with my friend google “Your server most like does not have GD (the built in PHP image processing library) enabled” but i don’t know have to troubleshoot

Thank you

To install GD library for images you’ll need to run the following as root

apt-get install php5-gd

APT for Debian/Ubuntu YUM for Centos/RHE

If you’ve already got it, the cli will tell you that you already are using the most recent version.
If you don’t, it’ll ask you if you really want to install it.
Install and try to change your Avatar again.